$ { \left[\begin{array}{r}{2} \\ {-1} \\ {3}\end{array}\right]+\left[\begin{array}{r}{1} \\ {-2} \\ {3}\end{array}\right] = {?} } $
Explanation: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{2}+{1} \\ {-1}+{-2} \\ {3}+{3}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{3} \\ {-3} \\ {6}\end{array}\right]}$